Perspectives on where our world is heading from a vantage point in Denver, Colorado.

29 September 2005

How Does Imprisonment Affect Crime?

Thirty two year lows in violent crime have been accompanied by a six fold increase in prison populations. The obvious question is, to what extent did the increase in imprisonment drive the decrease in crime? This question, indeed even minor nuances in the answer to this question, is far more important, from a practical perspective, than the debate over the death penalty in general, and far, far more important in my mind, at least, than nuances of the death penalty debate like the manner in which the death penalty is carried out.

Driven largely by increased prison sentences enacted as part of the "war on drugs" (there has been an eleven fold increase in the number of people imprisoned in drug cases since 1980) incarceration rates are far higher than they were a deacde ago. In 2005, there are 20,228 adults in prison in Colorado. In 1992, that number was 8,474. The prison population in Colorado has gone up 7% per year on average since 1992. Colorado is typical of the national trend.

No country in the world imprisons people at the rate that the United States does. Our incarceration rates are 5-8 times those of Canada and Western Europe, and much of the difference is due to much harsher prison sentences for drug crimes and property crimes. Those nations have frequently taken the stance that keeping people connnected to their communities and punishing them outside of prison is more effective than the benefical effects of short prison sentences that disrupt offenders lives without really being long enough to change the person, producing recidivism.

The trend towards long prison sentences is particularly pronounced for black men. One in eight black men aged 25-29 are currently in jail or prison. Nationally, about 29% of black men will do time at some point in their lives, and in Washington D.C., like most inner city neighborhoods, the rates are far higher: 75% of black men will eventually spend some time incarcerated.

Overall U.S. property crime rates are neither particularly high or particularly low, although the U.S. murder rate is very high, it violent crime rates are high, and according to the 2005 World Almanac (at page 164) almost 10% of people in prison are serving life sentences, many for murder. There are 35 people serving life sentences for each one on death row in the United States.

One of the better studies (cited at page 6 in the linked document) in the field finds that 12% of the increase in prison populations is due to an increase in the number of crimes committed (partially a product of increased population), 51% comes from felons who would previously not have gone to prison at all serving prison sentences, and 37% is due to longer sentences.

More to the point, about 25% of the drop in crime (see the references at page 12) has been attributed to increased incaceration, while the remainder has been attributed to a healthy economy, reduced crack use, and better policing and youth attitudes. Moreover, it isn't clear that all incarceration has been equally valuable. Which sentences do and do not prevent future crimes?

A Florida Study ranked the relative importance of different factors in the likelihood that a released offender will commit another crime. Not surprisingly, a poor disciplinary record while in prison, serving prison time in a high security facility, and a history of prior recidivism are connected with future criminal acts. People who commit economicly motivated crimes (burglary, property offenses and drug offenses) are also more likely to commit crimes again, than violent criminals and sex offenders. Crimes are more likely to be committed again by released prisoners who are young, have served shorter sentences, and are less educated. Blacks are more likely to reoffend, Hispanics are less likely to reoffend. Close post-release supervision also lowers the reoffense rate.

Boil it all down and you see basically two forces at work. First, someone is more likely to reoffend is crime was a way of life for them, rather than an isolated incident (often driven by economic factors and often illustrated by a history of offending), and second, crime is predominantly something done by men of a certain age who tend to cease to reoffend once they age and mellow.

The high recidivism rate for people who commit non-violent crimes is discouraging for proponents of sentencing reform, although not insurmountable. Many sentencing reformers would like to thin prison ranks by toning down sentences for drug offenders and property crimes, while they see the long sentences for violent criminals as an appropriate way to keep dangerous people locked up. But, if anything, the recidivism rates would point in the opposite direction.

A violent individual who commited a crime in a fit of passion, but was never economically dependent on crime as an occupation, who is released after having served a fairly long term, is likely to have mellowed in prison and unlikely to reoffend. There may be relatively little risk in releasing a violent offender who has already served 15 years in prison from another ten or twenty years of his sentence.

In contrast, a young high school dropout, who made a living through crime before going to prison, is unlikely to have reformed after serving a relatively short prison term and will often reoffend as a result of a lack of better options. Far more effort ought to be devoted to prevent the twenty-two year old car thief or burglar who is a high school dropout from reoffending after having served a two or three year sentence.

A few examples of the relative importance of the factors is instructive. Two more years in prison, both because of the prison time itself and because it make the offender older at the time of release, has enough beneficial effect to match the negative effect of a prior recidivism incident. The difference between being in a low security v. high security prison is roughly equivalent to a effect of a prior recidivism incident. The effect of a prison disciplinary incident is about as significant as the reduction in reoffense rates due to two more months in prison. A burglar of a given age and prison term is as likely to reoffend as a similarly situated murderer with two prior incidents of recidivism. One year of education reduces recidivism about as much as a three months longer prison sentence. Close post-release supervision is as effective at preventing recidivism as twenty more months of incarceration.

Violent crimes scare us more, but are less likely to be a way of life. Most crime is fundamentally economic in nature, and until the poverty that drives people to commit crimes for economic reasons is addressed, criminals have little choice but to persist in commiting crimes. Likewise, in the case of people who deal drugs primarily to support their own substance abuse habit, they are going to reoffend unless they have broken their habit. But, simply having someone keep a close eye on you in the critical period after you are released has an effect as well. Close post-relief supervision, on average, is cost effective on average, even if its costs $50,000 per prisoner, compared to longer sentences.

This conclusion is supported by data from other sources. One study reports that: 12.2% of non-sexual violent offenders reoffend, 13.4% of sex offenders reoffend, and 36.9% of other offenders reoffend. This doesn't mean that more care with serious offenses isn't in order. A repeat sex offense or aggrevated assault is far worse for society than a repeat burglary or car theft. But, it does confirm the Florida statistics and the trend in national statistics. Texas statistics show a less marked distinction between different offenses, but similar trends except with regard to sex offenses, for which it found high recidivism rates.

Indeed, one trend which is consistent with current sentencing trends that focus on long sentences for repeat offenders, is that people who have committed serious crimes in the past are far, far more likely to commit crimes in the future than members of the general public, and people who have multiple prior crimes are particularly likely to reoffend.

This still doesn't necessarily mean that putting those individuals in prison and throwing away the key makes sense. Indeed, recidivism statistics for people who have served prison sentences don't even go to the crux of the European argument. Are the recidivism rates of people who have served short terms for non-violent crimes higher than the recidivism rates of people who were punished in a manner other than a prison sentence (such as a German style "day fine" where the fine amount is linked to how much the offender could have earned during the time period of the otherwise applicable prison sentence)? If the recidivism rate is the same for someone in the community who is paying fines that cover the cost of his supervision, provide full restitution to the victim, and result in a penalty over and above that, as it is for someone who is incarcerated at a $30,000 a year public expense that results in no restitution to the victim, isn't the fine a better way to go?

But, the numbers do show that putting people who commit serious offenses in prison for a few years and then tossing them out into the outside world with little guidance, supervision or support, is practically an invitation to future criminal activity. The revolving door approach to criminal punishment doesn't work. Put another way, if a burglar is going to end up spending nine years in prison in any case, wouldn't it be better for that time to be served all at once, instead of in three or four separate sentences broken up by a dozen cases of burglary (most never resulting in court convictions) in between those sentences?

This post doesn't offer a final answer to this big issue, but it does, at least, look at the facts and begin to grapple with their implications.